When printing out the array backwards, you don't need to read from the file again, since you've already stored the values in the array. You have also done something odd with the curly braces, so that I'm not sure that the loop is doing what you want it to. So, you can change this:

Note how the braces start after the for ( i = 12... part. The way you had it before, only the line immediately after the for would be in the loop. I don't know if you meant to do that but the indentation suggested not.

Also, in C/C++ there is no automatic way to print out the contents of an array; you have to print each element explicitly (using the index to the element that you want to print), so you need to have cout << numbers[ i ] << " "; in a loop to print the whole array.

On a side note, there is a more succinct way to read a file like this, using algorithms:

#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
int main()
{
std::ifstream fin( "F:\problem5 YES.txt" );
if ( ! fin.is_open() ) // Use the "is_open" method to decide if the file is open
{
// Output to std error, not std out
std::cerr << "Cant open file" std::endl;
// Return here, rather than just carrying on
return -1;
}
// A std::vector for holding the values from the file
std::vector< int > v;
// Use the std::copy algorithm to copy values from the file into the vector
//
// The important thing here is that you can iterate over the contents of a
// file using a std::istream_iterator. The other "trick" is that the version
// of std::istream_iterator that has no argument (the second one used in the
// code below) represents the end of the stream that is being iterated over.
//
// std::back_inserter is an object that is able to insert values into a
// std::vector as they arrive. The vector will resize itself to take care
// of the new values
std::copy( std::istream_iterator< int >( fin ), std::istream_iterator< int >(),
std::back_inserter( v ) );
// Write the contents of the vector to screen
std::copy( v.begin(), v.end(), std::ostream_iterator< int >( std::cout, " " ) );
// Write the contents of the vector to the screen in reverse order
std::copy( v.rbegin(), v.rend(), std::ostream_iterator< int >( std::cout, " " ) );
return 0;
}

Containers (like std::vector), algorithms (like std::copy) and iterators (like std::istream_iterator) are a fundamental part of C++. They're also pretty cool, so definitely take some time to look them up :0)